Cows are considered the largest producer of methane globally, according to the US Environmental Protection Agency. The Food and Agriculture Organization of the United Nations has reports stating "The livestock sector is a major player, responsible for 18 percent of greenhouse gas emissions measured in [carbon dioxide] equivalent."

Reduction of methane produced by cows has long been thought to be a key green house gas reduction activity. Recently, Wageningen University researcher Van Zijderveld discovered that nitrate and sulphate additives in feed help reduce methane production in cow stomachs.

If their feed contains a small percentage of these substances the amount of this powerful greenhouse gas produced by sheep is halved, research by Sander van Zijderveld has shown.

While the research is in its early stages, there is potential to reduce methane production 16 to 30 percent.

A deft hand is needed to get the silage piles in the right form. From Modesto, CA, this article also shares with non-farmers what silage is, how it is harvested, and why it is used as feed for dairy cows.

Who knew that silage piles — those giant mounds of dairy feed covered with plastic sheeting — could be works of art?

A delicate touch helps when managing the piles, which can degrade if too much air gets inside them.

That's why Larry Pacheco tries to minimize the exposed surface when he removes some of the feed from a pile with a tractor.

Silage, which dairy farmers make by fermenting corn or other crops for a few weeks after harvesting, has become an important feed in the Northern San Joaquin Valley and elsewhere.

And it's another example of the sophisticated work behind the seemingly simple business of producing food.

North valley farmers produced about $212 million worth of silage last year, according to county crop reports.